Your skin is susceptible to many invaders. Various environmental and medical conditions, infections, viruses, parasites, fungi and heat can cause abnormal melanin production, which results in deposits in the skin that can cause red spots and blemishes. Though not life-threatening, these blemishes are often unsightly or even painful. Some skin conditions clear up naturally, while others require medical treatment.
Infections can cause red spots and bumps on the skin. Skin infections can be bacterial, viral or as a result of a fungus. Impetigo is a skin infection from bacteria that live in the top layers of the skin and causes red sores that can ooze. Warts and shingles are examples of viral infections. The virus can lie dormant for years and emerge as red spots, bumps and blemishes. Tinea fungus infections such as ringworm can be contagious, affecting the arms, legs or chest.
An allergy is a reaction that happens when the immune system recognizes something as foreign or dangerous to your body. Cells under your skin release histamine in response to an allergen. Exposure to toxins or irritants such as chemicals, cosmetics and soaps, dyes in clothing, dust mites, pollen or mold in the air, pet dander, insect stings and food can cause reactions, which may result in red spots or blemishes to appear on the skin. Antihistamines or steroids may provide some relief.
There are many types of acne, all of which can cause red spots to appear on the skin. Often acne is caused by a clogged pore. Inflammation from bacteria around the hair follicle may cause the formation of raised, red bumps. Acne from cysts can be more severe, developing deeper in the skin.
Medicines That Cause Skin Problems
Medications can cause a drug rash, most commonly resulting from the use of antibiotics, anti-seizure medications and diuretics. The rash can begin as red spots and spread to all areas of the body. Usually after discontinuing the medication, drug rashes disappear within three weeks.
Parasitic Skin Reactions
Exposure to parasitic organisms can cause a severe and persistent skin reaction causing red spots and blisters. Swimmer’s itch is an example of a parasite from contaminated water that can enter the superficial layers of exposed skin. When the organism dies, a skin reaction develops that is characterized by a red, raised itchy rash.
Heat rash, also known as prickly heat or miliaria, can result from excessive sweating or exposure to hot humid conditions. It appears as red clusters of small red or clear blister-like bumps. Heat rash can be itchy, but is not serious and can be treated by keeping the affected area cool and dry and avoiding tight clothing.
Rosacea is an inflammatory skin condition in adults that produces small, red, pus-filled bumps. Rosacea is often cyclic and flares up periodically. Though treatments can control and reduce symptoms, there is no cure for rosacea.